JPH10219165A - Ink jet recording fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-base ink jet recording ink being excellent in water resistance and weathering resistance and having a good dispersion stability and stability of delivery through nozzles. SOLUTION: This fluid is prepared by dispersing carbon black subjected to absorption treatment with humic acid, its derivative or its salt in an aqueous liquid. The carbon black subjected to the treatment is one prepared by bringing carbon black into contact with a liquid prepared by dispersing or dissolving humic acid or its derivative in a water containing an alkali and allowing the surface of the carbon black to absorb humic acid or the salt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording liquid having excellent dispersion stability and good ejection stability at a nozzle.

[0002]

2. Description of the Related Art Conventionally, ink jet recording liquids have been disclosed in JP-A-53-61412 and JP-A-54-89.
As disclosed in JP-A-811 and JP-A-55-65269, those obtained by dissolving a water-soluble dye such as an acid dye, a direct dye or a basic dye in a glycol solvent and water are often used. . However, as the water-soluble dye, a dye having high solubility in water is generally used in order to obtain the stability of the recording liquid, and the water resistance of the ink jet recorded matter is poor, and the ink is easily recorded when water is spilled. There was a problem that bleeding of some dyes occurred.

In order to improve such poor water resistance,
As disclosed in JP-A-56-57862, attempts have been made to change the structure of a dye or to prepare a recording solution having a strong basicity. Also, Japanese Patent Application Laid-Open No. 50-490
No. 04, JP-A-57-36692 and JP-A-5-36969.
As disclosed in Japanese Patent Application Laid-Open No. 9-20696 and Japanese Patent Application Laid-Open No. Sho 59-146889, improvement of water resistance has also been attempted by making good use of the reaction between a recording paper and a recording liquid. Although these methods have a remarkable effect on specific recording paper, they lack versatility in that they are restricted by recording paper, and when a non-specific recording paper is used, a water-soluble dye is used. In many cases, the recording liquid cannot provide sufficient water resistance of the recorded matter.

[0004] Examples of recording liquids having good water resistance include those in which an oil-soluble dye is dispersed or dissolved in a high boiling point solvent and those in which an oil-soluble dye is dissolved in a volatile solvent. There is a problem of emission of water, which is environmentally unfavorable.
In addition, there is a problem that solvent recovery or the like is required depending on a case where a large amount of recording is performed or where the apparatus is installed. Therefore, in order to improve the water resistance of the recorded matter, a recording liquid in which a pigment is dispersed in an aqueous medium has been developed.

However, unlike pigments, it is very difficult to disperse pigments as fine particles and to maintain a stable dispersion state. On the other hand, in the recording liquid for ink jet, the nozzle diameter has been reduced as the resolution of the printer has been increased, and accordingly, the particle diameter of the pigment needs to be reduced. Further, there is also a demand for transparency on a par with dyes in forming an image on a transparent base material such as an overhead projector, and miniaturization is also demanded from the viewpoint of coloring of pigments.

From this point of view, various studies have been made on the finer and dispersed pigments. Particularly, in the case of carbon black, there are many ink jet recording liquids having good ejection stability due to oxidation treatment and grafting technology. It has been devised. In general, the surface of the carbon black particles is lipophilic, and thus may be subjected to an oxidation treatment for improving wettability and facilitating dispersion in aqueous applications. It is known that this treatment generates an acidic functional group such as a carboxyl group or a phenolic hydroxyl group on the surface of the carbon black particles, and improves the dispersibility in an aqueous system. In the oxidation treatment of carbon black, the case where a hydrophilic functional group is directly introduced to the particle surface and the case where the carbon black is decomposed by oxidation and the decomposition product is hydrophilic, so that the dispersibility in an aqueous system is improved. There is. As an example of the latter, it has been reported that a decomposition product similar to humic acid is generated on the surface of carbon black particles by ozone oxidation or plasma oxidation, and the larger the amount of the generated product, the better the dispersibility in an aqueous system. (JBDonn
et: Carbon, 10,737,1972), (Tatsuhiko Ihara: Nikka, 1575,19)
84).

[0007] Humic acid is an alkali-soluble amorphous high-molecular organic acid contained in young coals such as peat and lignite having a low degree of coalification. This humic acid is roughly classified into natural products and artificial products (including nitrohumic acid), and is used for applications such as dyes for plastics and papers, dispersants for inks, and dispersants for ceramics. Is well known. However, when this humic acid is used as a dispersant for an inkjet recording liquid, it causes troubles such as deterioration of ejection properties, clogging, and storage stability of the ink, and cannot be used. This is because humic acid is an amorphous high molecular organic acid, and its molecular weight is 10
^{2-10 6} and extensively distributed, high molecular weight moiety or aggregated portions of the dispersion state of the humic acid salt solution is considered to have caused. In particular, in a thermal type printer, a patent has been reported that discusses the necessity of suppressing humic acid to 2 ppm or less as a water component used in an aqueous dye system (Japanese Patent Application Laid-Open No. 08-259834).

As described above, the modification of the pigment particle surface has not yet escaped from the development stage in terms of its effect and cost.
In other words, gas-phase oxidation has a problem that the degree of oxidation is not sufficient because the degree of oxidation is not sufficient, and dispersion stability is insufficient, and liquid-phase oxidation and grafting are costly in terms of processes and are not sufficient in terms of productivity. I have. Furthermore, regarding the use of humic acid in carbon black, there is a problem that even if humic acid or a humate is simply used as a dispersant for carbon black, satisfactory discharge stability and printing quality cannot be obtained. .

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide an aqueous ink jet recording liquid having stable dispersibility and good ejection stability at a nozzle. It is in.

[0010]

Means for Solving the Problems The inventors of the present invention have proposed an ink jet recording liquid in which carbon black is dispersed in an aqueous liquid, and the hydrophilicity of humic acid generated on the surface of carbon black particles by the oxidation treatment of carbon black. Focusing on the effect as a dispersant and the dispersant, by using the treated carbon black obtained by adsorbing the surface of the carbon black particles with low molecular weight humic acid or a derivative thereof, or a salt thereof, it has a stable dispersibility. It has been found that an aqueous inkjet recording liquid having good ejection stability at the nozzle can be obtained, and the present invention has been accomplished.

That is, according to the present invention, the following ink jet recording liquid is provided. (1) An ink jet recording liquid comprising carbon black adsorbed with humic acid or a derivative thereof, or a salt thereof, dispersed in an aqueous liquid. (2) The ink jet recording liquid according to (1), wherein the salt of humic acid or a derivative thereof is an amine salt. (3) The molecular weight of humic acid or its derivative is 10 ⁵
An inkjet recording liquid according to the following (1) or (2). (4) The ink jet recording liquid according to any one of (1) to (3), wherein the treated carbon black has an average particle diameter measured by a laser scattering method of 10 to 150 nm. (5) The ink jet recording liquid according to any one of (1) to (4), which contains the treated carbon black in an amount of 0.1 to 10% by weight in solid content. (6) A solution prepared by dispersing or dissolving humic acid or a humic acid derivative in alkali-containing water with the treated carbon black is brought into contact with the carbon black, and a humate or a humic acid derivative salt is adsorbed on the surface of the carbon black particles. The recording liquid for inkjet according to (1), wherein the treated carbon black is used.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The carbon black used in the present invention is prepared by a channel black method, a furnace black method,
A pigment produced by various methods such as the acetylene black method, and any of acidic carbon, neutral carbon and basic carbon can be used. Specific examples of carbon black include MA-7, MA-8, and MA- manufactured by Mitsubishi Chemical Corporation.
100, # 2200B, # 2600, MCF88, N
o. 10B, no. 33, no. 40, no. 4000
B, No. 52, CF-9, etc. Reg made by Cabot Corporation
al 400R, 660R, 330R, MOGUL L
Degussa Color Black FW1, F
W18, S170, S150, Printex U, 3
REVE manufactured by Columbian Carbon Co., Ltd.
N 1255 and the like.

[0013] The carbon black is preferably in the form of fine particles.
A particle having a diameter of 15 to 35 nm is used, and the value as an average particle diameter when dispersed in water is 10 to 150 nm.
(Measured value by laser scattering method) is good.

The humic acid, humic acid salts, and humic acid derivatives (including nitrohumic acid) used in the present invention are available as reagents or industrial products, and the industrial products are classified into CH type, CHA type and CHN type depending on the molecular weight. Yes, the low molecular weight CHA type is preferred. Humic acid derivatives are
It means that it is polymerized by reacting with aldehydes, humins and phenols. Since these derivatives are used after being dissolved in any one of alkali metal salts, ammonium salts and amine salts, water-insoluble ones having advanced polymerization are not suitable for the present invention. As the salt type, for example, N
a, NH4, etc., and any of them can be used. However, when an amine salt is used due to stability over time and heat resistance, for example, dimethylaminoethanol, diethylaminoethanol, monoethanolamine, etc. may be used as the amine. preferable.

The aqueous humate solution is prepared by adding 0.1 to 20 parts by weight of humic acid to 100 parts by weight of ion-exchanged water or distilled water from which metal ions have been removed. At the time of the addition, the aqueous solution is stirred, and the humic acid is added little by little so as not to form a mamako, and the mixture is heated to about 40 to 50 ° C. Ammonia or amine has a pH of aqueous solution of humate of 7-10.
Add an amount that can be adjusted to the extent. An aqueous humate solution can be prepared by stirring for about 1 to 2 hours. Before the prepared humate aqueous solution is adsorbed on the desired carbon black, the polymer portion is previously removed by molecular weight fractionation, or
It is preferable to remove the sediment by centrifugation. For separation of the high molecular weight portion, 10 ⁵ or more are separated and removed using chromatography such as GPC. When a centrifugal separator is used, it is rotated at about 3000 rpm or more for about 30 to 1 hour, and the supernatant is used. In either case,
It is preferable to sufficiently filter using a filter having a pore size of 3 μm or less, preferably a filter having a pore size of 1.0 μm or less, and more preferably a filter having a pore size of 0.45 μm or less.

The humic acid salt thus prepared is adsorbed on the surface of the carbon black particles by contacting it with carbon black, and the adsorbed carbon black is dried to form a powder or a dispersion liquid without a drying step. Or it can be used as a wet cake. In either case,
The excess humate which has not been adsorbed is preferably removed by washing and filtering.

As the adsorption treatment, carbon black may be simply added to the aqueous solution of humate and left alone, but dispersion by ultrasonic waves, stirring, mixing with a homogenizer, use of a sand mill or the like can be used as appropriate. The mixing ratio of the carbon black and the humate varies depending on the particle size, surface area and oil absorption of the carbon black, but is typically about 0.1 to 20 parts by weight with respect to the carbon black. It is necessary to balance.

The average particle size of the treated carbon black measured by a laser scattering method is 10 to 150 nm, and more preferably 1 to 150 nm.
It is preferably from 0 to 100 nm. When the treated carbon black having such a particle size is used, the filtration operation in the production of the recording liquid is easy, and the sedimentation of the carbon black over time is small when the recording liquid is stored. It is preferable from the viewpoint of dispersibility that the treated carbon black pigment is contained in a range of 0.1 to 10 parts by weight in solid content in 100 parts by weight of the inkjet recording liquid.

The treated carbon black pigment which has been subjected to the humic acid adsorption treatment is added to an aqueous liquid so as to have a concentration of about 10 to 40% by weight, and may be used as it is or by performing a normal dispersion for a short time. An aqueous carbon black pigment dispersion can be easily obtained without passing through a black pigment drying step. Since this aqueous carbon black pigment dispersion is a dispersion of treated carbon black pigment fine particles showing good dispersibility without adding a dispersant, it is simply diluted to a concentration suitable for printing, and further added as necessary. An ink-jet recording liquid can be obtained by adding an agent and filtering, but it is preferable to further disperse the ink with a dispersing machine using a dispersant or the like to obtain a stable and highly fixable ink-jet recording liquid. When the dispersion is further carried out with a usual dispersing machine such as a sand mill, the carbon black pigment is fine, and a stable dispersion state of the inkjet recording liquid can be easily obtained in a short time without significantly increasing the dispersion time.

For the production of an ink jet recording liquid, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, or the like may be used. A disperser or the like that disperses by a cavitation effect in a high-pressure room can be used. Also,
Mixing and stirring can be performed by a high-speed disperser, emulsifier, or the like, in addition to stirring by a stirrer using ordinary blades.

The ink jet recording liquid of the present invention is preferably sufficiently filtered through a filter having a pore size of 3 μm or less, preferably 1.0 μm or less, more preferably 0.45 μm or less. Prior to filtration of the filter, those having a large particle size can also be removed by centrifugation, thereby reducing clogging in the filtration by the filter and prolonging the service life of the filter.

As the aqueous liquid, water and, if necessary, an aqueous solvent can be used. As the water, ion-exchanged water or distilled water from which metal ions and the like have been removed can be used, and the water is preferably contained in the recording liquid in a range of 50 to 98% by weight. The aqueous solvent prevents drying and solidification of the recording liquid at the nozzle portion, stably sprays the recording liquid, and also functions as a humectant. It is preferable to use within the range.

As the aqueous solvent, ethylene glycol,
Diethylene glycol, propylene glycol, triethylene glycol, polyethylene glycol, glycerin, tetraethylene glycol, dipropylene glycol, ketone alcohol, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether,
Examples include ethylene glycol monoethyl ether, 1,2-hexanediol, N-methyl-2-pyrrolidone, substituted pyrrolidone, 2,4,6-hexanetriol, tetrafurfuryl alcohol, 4-methoxy-4-methylpentanone and the like. . For the purpose of accelerating the drying of the recording liquid, alcohols such as methanol, ethanol and isopropyl alcohol can be used.

The ink jet recording liquid of the present invention preferably contains an aqueous resin in order to enhance the fixability to a printing medium. The aqueous resin also contributes to the dispersibility of the carbon black-treated pigment. When the printing medium has ink acceptability, the aqueous resin is not required. As the aqueous resin, a water-soluble resin that dissolves in water, a water-dispersible emulsion resin that disperses in water, and a colloidal dispersion resin are used alone or in combination. Specific examples of the aqueous resin include water-soluble resins and water-dispersible resins such as acrylic, styrene-acryl, polyester, polyamide, polyurethane, and fluorine.

For the purpose of fixing to a printing medium, the aqueous resin is preferably used in the recording liquid in an amount of 0.1 to 10% by weight. If less than this amount,
The carbon black pigment cannot be firmly fixed. On the other hand, when the amount is larger than this amount, the viscosity of the recording liquid is excessively increased and the ejection stability is decreased. When a water-soluble resin is used as the water-based resin, the viscosity of the recording liquid tends to be high, but the viscosity of the water-dispersible resin can be suppressed low, and the water resistance of the recorded matter can be reduced. It can be further improved. When an aqueous resin is used, it is preferable to add a neutralizing agent such as ammonia, an amine or an inorganic alkali to adjust the solubility or dispersion stability of the aqueous resin.

The ink-jet recording liquid of the present invention contains a dispersant, a surface tension, a regulator for penetration, a fungicide, a chelating agent,
Additives such as an antifoaming agent can be blended as required.
The dispersant can be used to maintain stable dispersion of the carbon black pigment, when the aqueous resin cannot be used for the dispersant, or for more stable dispersion. As the dispersant, an anionic, nonionic, cationic, or zwitterionic activator can be used.

Examples of the anionic activator include fatty acid salts, alkyl sulfate salts, alkyl aryl sulfonates, alkyl naphthalene sulfonates, dialkyl sulfonates, dialkyl sulfosuccinates, alkyl diaryl ether disulfonates, and alkyl phosphoric acids. Salt, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl aryl ether sulfate, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester salt, glycerol borate fatty acid ester, polyoxyethylene glycerol fatty acid ester, etc. Can be illustrated.

Examples of the nonionic activator include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, Examples thereof include glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, fluorine-based, and silicon-based nonionic activators.

Examples of the cationic activator include an alkylamine salt, a quaternary ammonium salt, an alkylpyridinium salt, an alkylimidazolium salt and the like. Examples of the zwitterionic activator include alkyl betaine, alkyl amine oxide, phosphadyl choline and the like.

When the printing medium of the recording liquid has permeability like paper, a penetrating agent can be added to stop the penetration of the recording liquid and to speed up the apparent dryness. Examples of such penetrants include glycol ethers such as diethylene glycol monobutyl ether exemplified as aqueous solvents, alkylene glycols, alkylene diols, polyethylene glycol monolauryl ether, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium oleate, dioctyl sulfosuccinic acid Sodium or the like can be used. The penetrant has a sufficient effect when used in an amount of not more than 5% by weight of the recording liquid, and if it is more than this, bleeding of printing and paper loss (print through) occur, which is not preferable.

The fungicide can be added to prevent the generation of mold and bacteria in the recording liquid. As an antifungal agent,
Sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, zinc pyridinethione-1-oxide, 1,2-benzisothiazolin-3-one, amine salt of 1-benzisothiazolin-3-one and the like are used. Can be These are contained in the recording liquid at 0.05%.
It is preferably contained in the range of 1.0 to 1.0% by weight.

The chelating agent blocks metal ions in the recording liquid, and can be added to prevent deposition of metal at the nozzle portion and precipitation of insoluble substances in the recording liquid. As the chelating agent, ethylenediaminetetraacetic acid, sodium salt of ethylenediaminetetraacetic acid, diammonium salt of ethylenediaminetetraacetic acid, tetraammonium salt of ethylenediaminetetraacetic acid, and the like are used. These are contained in the recording liquid in an amount of from 0.005 to 0.5.
Preferably, it is contained in the range of 5% by weight.

Further, in order to adjust the pH of the recording liquid and obtain stability of the recording liquid or stability with the recording liquid pipe in the recording apparatus, a pH adjuster such as an amine, an inorganic salt or ammonia, and a buffer such as phosphoric acid. Liquids can be used. Further, an antifoaming agent can be added in order to prevent the recording liquid from circulating or moving inside the pipe or inside the pipe, or from generating bubbles during the production of the recording liquid. In addition, adjustment of the hue of carbon black,
For the purpose of giving a concentration or the like, a dye can be used in such a form that there is no problem in water resistance and light resistance. Depending on the use of the dye, the dispersion stability of the carbon black may be deteriorated. Therefore, it is necessary to limit the use of the carbon black to 40% by weight or less, preferably 25% by weight or less.

As the dye, there may be used water-insoluble dyes such as disperse dyes and oil-soluble dyes, direct dyes, acid dyes, basic dyes and the like, which are insolubilized by lake formation, reactive dyes, metal-containing dyes and the like. Purified dyes from which salts have been removed are preferred. Specific examples of the dye include C.I. I. Direct black 17, 19, 32, 51, 71, 108, 146, 1
54, 166, C.I. I. Add Black 2, 7, 24,
26, 31, 52, 63, 112, 118, C.I. I. Basic Black 2, C.I. I. Direct Blue 6, 2
2, 25, 71, 90, 106, C.I. I. Acid Blue 9, 22, 40, 59, 93, 102, 104, 11
3, 117, 120, 167, 229, 234, C.I.
I. Basic Blue 1, 3, 5, 7, 9, 24, 2
5, 26, 28, 29, C.I. I. Direct Red 1,
4, 17, 28, 83, C.I. I. Acid Red 1,
6, 32, 37, 51, 52, 80, 85, 87, 9
2, 94, 115, 180, 256, 315, 317.
C. I. Basic Red 1, 2, 9, 12, 13, 1
4, 37, C.I. I. Direct Yellow 12, 24, 2
6, 98, C.I. I. Acid Yellow 11, 17, 23,
25, 29, 42, 61, 71, C.I. I. Basic yellow 11, 28. C. I. Direct orange 34, 3
9, 44, 46, 60, C.I. I. Direct violet 47, 48, C.I. I. Direct Brown 109,
C. I. Direct Green 59, C.I. I. Acid orange 7, 19, C.I. I. Acid Violet 49,
C. I. Basic violet 7, 14, 27 and the like can be exemplified. Urea, dimethyl urea and the like can be added as other additives.

The recording liquid is preferably adjusted as a liquid having a viscosity of 0.8 to 15 centipoise (25 ° C.), depending on the type of the recording apparatus. The surface tension of the recording liquid is 25-60
dyn / cm is preferable, and the pH is not particularly limited.
To 12 and preferably 7 to 10 in terms of dispersion stability of the treated carbon black.

Hereinafter, the present invention will be described based on examples. In the examples, parts and% mean parts by weight and% by weight, respectively. (Example of preparing aqueous solution of humic acid salt or humic acid derivative)
An aqueous solution of a humate or a humic acid derivative salt was prepared according to the formulation shown in Table 1. Humic acid (or humic acid derivative) is gradually added to ion-exchanged water with stirring, and care is taken not to form a mamaco state at this time. The aqueous system is p
Add an alkali component so that it becomes about H8,
And heat and stir for about 1 hour. The aqueous solution of humic acid (or humic acid derivative) salt is centrifuged at 10,000 rpm, and the supernatant is filtered through a 0.45 μm filter to obtain a prepared solution. (Treatment Examples 1 to 8 of Carbon Black) Carbon black was treated with the composition shown in Table 1 as follows. A mixture of carbon black and a humic acid (or humic acid derivative) salt preparation is dispersed in a sand mill for about 1 hour, washed several times with ion-exchanged water to obtain an aqueous dispersion of treated carbon black (solid content: 15%). Was.

[0037]

[Table 1]

* 1 Carbon black (MA-7 manufactured by Mitsubishi Chemical) * 2 Carbon black (MOGUL manufactured by Cabot)
L) * 3 Carbon black (Color Bl made by Degussa)
ackFW18)

(Synthesis example of water-based resin) According to the synthesis method of acrylic resin, methyl methacrylate (MMA), ethyl acrylate (EA), and methacrylic acid (MAA) were copolymerized with the following monomer composition (molar ratio), A copolymer was synthesized. MMA EA MAA molecular weight Synthesis Example 1 10.5 0.5 10000 2 1 1.0 2.0 20,000 3 12.0 1.0 20,000 4 1 2.0 3.0 25000 5 1 3.0 1.0 28000 6 1 3.0 0.5 18000

(Examples 1 to 12) The raw materials shown in Table 2 were charged into a sand mill at the compounding ratio (weight ratio) shown in Table 2,
Dispersion was performed for ~ 4 hours. After that, 10,000 rpm
m, and the mixture was filtered through a 0.45 μ filter to prepare an inkjet recording liquid.

[0041]

[Table 2]

Dispersant 1 Nonionic activator "Emulgen 420" manufactured by Kao Corporation Dispersant 2 Nonionic activator "Emulgen A-9" manufactured by Kao Corporation
0 "Dispersant 3 Nonionic dispersant" SOLSPERS
27000 "Acrylic resin 1 Acrylic resin emulsion" W-251 "manufactured by Nippon Polymer Co., Ltd. 40% solid content Acrylic resin 2 Acrylic resin emulsion" Emapoly TYN-50 "manufactured by Gifu Shellac, 44% solid content Acrylic resin 3 Acrylic resin manufactured by Johnson Polymer Aqueous resin solution “Johncryl 62”, solid content 31% Acrylic resin 4 Acrylic resin aqueous solution “Johncryl 61J” manufactured by Johnson Polymer, solid content 31%

Neutralizing agent 1 Dimethylaminoethanol Neutralizing agent 2 Diethylaminoethanol Neutralizing agent 3 Monoethanolamine Wetting agent 1 Glycerin Wetting agent 2 Diethylene glycol Solvent 1 Isopropyl alcohol Solvent 2 Ethyl alcohol Solvent 3 N-methyl-2-pyrrolidone Antifungal Agent 1 “PROXEL GXL” manufactured by Zeneca Company 2 Fungicide 2 “Sodium Omazine” manufactured by OHLIN Company Chelating agent Sodium salt of ethylenediaminetetraacetylic acid

The recording liquid obtained in the examples was evaluated for dispersibility by the following method. Further, the recording liquid obtained in the examples was applied to an ink jet printer (“MJ7” manufactured by Epson Corporation).
00V2C ”), and recording was performed, and the water resistance, rub resistance, and light resistance of the recorded matter were evaluated by the following methods. Table 3 shows the results. Further, when the recording liquid obtained in the example was stored at -40 ° C for one week and then naturally thawed, the initial viscosity was maintained and stable ejection characteristics were exhibited. When stored in a constant temperature bath at 50 ° C. for one month, the initial viscosity was maintained and stable injection characteristics were exhibited. Also, -4
A cycle of 7 hours at 0 ° C, 7 hours at room temperature, and 7 hours at 50 ° C
When the printing was repeated twice, the initial printing characteristics and the physical properties of the recording liquid were maintained.

Water-resistant copy paper "Xerox 402"
4 ", left for 6 hours, immersed in tap water for 5 minutes, and measured the OD value before and after the test to show the remaining rate. Abrasion Resistance The change in the printed area when the solid printed on the art paper was rubbed three times with a wet cotton swab was visually evaluated. Lightfastness After printing and laminating on the coated synthetic paper, it was exposed for 500 hours with a fade meter, and the color difference before and after exposure was determined. Dispersibility A change in the particle size of the recording liquid after storage at 50 ° C. for 7 days was measured. Good: Change of less than 15 nm Bad: Change of 15 nm or more

[0046]

The recording liquid of the present invention is a water-dispersion type ink-jet recording liquid in which carbon black is dispersed in an aqueous liquid, but has a stable dispersibility and a good discharge stability at a nozzle. To prepare documents in the office,
It can be used in the fields of cardboard marking, numbering, barcode, etc., on-demand printing, and simple printing.

Claims (6)

[Claims] 1. An ink jet recording liquid comprising carbon black adsorbed with humic acid or a derivative thereof, or a salt thereof, dispersed in an aqueous liquid. 2. An ink jet recording liquid according to claim 1, wherein the salt of humic acid or a derivative thereof is an amine salt. 3. A humic acid or a derivative thereof having a molecular weight of 1
3. The ink jet recording liquid according to claim 1, which has a value of ^0.5 or less. 4. The ink-jet recording liquid according to claim 1, wherein the average particle diameter of the treated carbon black measured by a laser scattering method is 10 to 150 nm. 5. The treated carbon black in a solid content of 0.1 to
5. The ink jet recording liquid according to claim 1, wherein the recording liquid comprises 10% by weight. 6. A solution prepared by dispersing or dissolving humic acid or a humic acid derivative in water containing an alkali, wherein the treated carbon black is brought into contact with the carbon black to form a humate or a humic acid derivative salt on the surface of the carbon black particles. 2. The ink jet recording liquid according to claim 1, which is a treated carbon black to which is adsorbed.